Ah yeah 657 isn't very far up the HOOT, only about 1 mile from the parking access at least. FWIW they are starting construction of the bridge that the HOOT will take over rt3/36. Not sure when that stretch will be done and paved but perhaps soon. Might add some options now, instead of having to take the roads through Centerburg to get to it. Unfortunately the stretch of railbed between the current HOOT section and the Deleware Co section hasn't been able to be acquired from the current landowners, so there may be a gap from Sunbury to Centerburg for a long time.

If you make it to the end of the HOOT in Mt Vernon - where they just restored the train depot, be sure to use the new electronic crossing there across S Main St and stop into Whits Frozen Custard which sits trailside on the other side of S Main.

And if you ever see a barefoot dude running or cycling around there, 99% chance that it is me lol.
Have fun on the OTET trip if you're going. Sounds like a blast.